Jarhead, fantastic video that had my heart-rate well-elevated and my palms sweating -- despite your very level-voiced narration ;) Mishigama's helming in the vid was impressive, as it is VERY evident that you were having a hella Neuse sleigh ride that day, and the slack-bilged SP is sneaky fast but a high-roller on that point of sail (NOT my favorite in the SP). Did you have (or consider having) water in the ballast tanks?
You queried Dawn Patrol's use of mizzen only in those conditions. Comparing my SP with its fine ends, high CG, leeboards, and slack bilges, with my now-split-rigged wuzza-Lightning having a hard-chined, beamier, broader-transomed, c/b-fitted hull form quite similar to the CS designs, it is evident that these latter types are much more capable of standing up to sail area aft.
In any case, the after mast on all these designs is almost amidships, and sail set there when running is 1) closer to the CLR and point of rotation, 2) easier to reef safely, 3) exerts less downward pressure on the bow and therefore minimizes any tendency to bury it (a real concern in those conditions), and 4) maintains weather helm so that the vessel will naturally round up and heave-to -- especially important in the sharpie-type CS and Lightning with low transom that's vulnerable to being pooped by following seas. Dawn Patrol also has a significant amount of windage forward due to its doghouse, especially when running, that will "balance" the mizzen's area.
An interesting alternative for all of these split-rigs is a storm-stays'l (like a 420 dinghy's 30sf jib -- $125? from Intensity Sails) flown off the mizzen: it sets flying, right in the center of the boat (making the boat quite neutral helm and easy to steer -- and the tack can be moved around to further accomplish that), has very low CE (and no head-knocker / wave-snagging boom!), and is easily/instantly doused. I think you were on the beach following the NCC-13 cancellation when ZTH and I set off to run down Core Sound in my SP flying only this stays'l (for the first time), and I can report that it worked brilliantly (and generated 8kts!). If the tack were set in the area of, say, your weather leeboard bolt, or forward oarlock socket, you could definitely fly the stays'l directly over your cuddy while in use.
And the 420 jib-stays'l is good for more than just running. Under just this sail, the boat would sail up to a beam reach and perhaps higher, if set and trimmed appropriately.
And about that sliding... It's a fine line between slipping and tripping in the leeboarded SP particularly! Again, a tip of the hat to you guys -- and to your solo performance in the also-"interesting" EC'15.
DKHT
